神野 信夫

OBJECTIVE To assess effects of vertebral distraction-fusion techniques at a treated segment (C5-C6) and an adjacent segment (C4-C5) of canine cervical vertebrae. SAMPLE Cervical vertebrae harvested from cadavers of 10 skeletally mature Beagles. PROCEDURES Three models (intact, titanium plate, and polymethylmethacrylate [PMMA]) for stabilization of the caudal region of the cervical vertebrae (C4 through C7) were applied to the C5-C6 vertebral segment sequentially on the same specimens. Biomechanical assessments with flexion-extension, lateral bending, and axial rotational tests were conducted after each procedure. Range of motion (ROM) for a torque load applied with a 6-axis material tester was measured at C4-5 and C5-6 and calculated by use of a 3-D video measurement system. RESULTS In both the plate and PMMA models, ROM significantly increased at C4-5 and significantly decreased at C5-6, compared with results for the intact model. The ROM at C5-6 was significantly lower for the plate model versus the PMMA model in lateral bending and for the PMMA model versus the plate model in axial rotation. Conversely, ROM at C4-5 was significantly higher in axial rotation for the PMMA model versus the plate model. No significant differences were identified in flexion-extension between the PMMA and plate models at either site. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study suggested that vertebral distraction and fusion of canine vertebrae can change the mechanical environment at, and may cause disorders in, the adjacent segment. Additionally, findings suggested that effects on the adjacent segment differed on the basis of the fusion method used.

Muscle lesions and decreased numbers of peripheral nerve branches have been reported in the soft palates of dogs presenting with brachycephalic airway obstruction syndrome (BAOS). Myosin adenosine triphosphatase staining was employed to investigate whether muscle lesions in the elongated soft palate (ESP) of dogs with BAOS reflect the presence of denervation. Soft palates were collected from nine brachycephalic dogs during surgical intervention for BAOS and from five healthy beagle dogs as controls. In the control soft palates, myofibres with relatively uniform diameters and a random mosaic pattern of type I and II myofibres were observed in the palatinus muscle (PM), while almost all of the myofibres in the levator veli palatini muscle (LVPM) were of type II. In the ESPs, small group atrophy, large group atrophy and angular-shaped atrophy were observed in myofibres of the PM and rarely in the LVPM. Fibre type grouping and an increase in type IIC myofibres were found only in the PM. Morphometric analysis of ESPs revealed a significant increase in the number of type I and II myofibres in the PM showing atrophy or hypertrophy compared with controls. A significant increase in atrophic type II myofibres was found in the LVPM of affected dogs. Myopathy consistent with denervation was observed in the PM, but rarely in the LVPM, of ESP specimens. The results suggest that the myopathy seen in dogs with ESP may partly reflect atrophy of myofibres resulting from damage to peripheral nerve branches, with subsequent reinnervation of myofibres. (C) 2016 Elsevier Ltd. All rights reserved.

Intramedullary bone marrow-derived mononuclear cell (BM-MNC) transplantation has demonstrated neuroprotective effects in the chronic stage of spinal cord injury (SCI). However, no previous study has evaluated its effects in the acute stage, even though cell death occurs mainly within 1 week after injury in all neuronal cells. Moreover, the mechanism underlying these effects remains unclear. We aimed to investigate the survival of intramedullary transplanted allogeneic BM-MNCs and the production of growth factors after transplantation to clarify the therapeutic potential of intramedullary transplanted BM-MNCs and their protective effects in acute SCI. Sprague-Dawley rats were subjected to traumatic SCI and received intramedullary transplantation of EGFP BM-MNCs (n = 6), BM-MNCs (n = 10), or solvent (n = 10) immediately after injury. To evaluate the transplanted BMMNCs and their therapeutic effects, immunohistochemical evaluations were performed at 3 and 7 days post-injury (DPI). BM-MNCs were observed at the injected site at both 3 (683 +/- 83 cells/mm(2)) and 7 DPI (395 +/- 64 cells/mm(2)). The expression of hepatocyte growth factor was observed in approximately 20% transplanted BMMNCs. Some BM-MNCs also expressed monocyte chemotactic protein-1 or vascular endothelial growth factor. The demyelinated area and number of cleaved caspase-3-positive cells were significantly smaller in the BM-MNC-transplanted group at 3 DPI. Hindlimb locomotor function was significantly improved in the BM-MNCtransplanted group at 7 DPI. These results suggest that intramedullary transplantation of BM-MNCs is an efficient method for introducing a large number of growth factor-producing cells that can induce neuroprotective effects in the acute stage of SCI. (C) 2016 Elsevier Ltd. All rights reserved.

Objectives The objectives of this study were to establish a magnetic resonance imaging-based classification system for canine hyperadrenocorticism according to pituitary gland extension, determine indications for trans-sphenoidal hypophysectomy, and clarify the prognosis for each disease grade. Methods A 5-point classification system (Grades 1 to 5) was developed based on tumour extension in dorsal and cranio-caudal directions. Cases were then classified as Type A: no arterial circle of Willis or cavernous sinus involvement and Type B: cases in which these blood vessels were involved. Results Medical records and magnetic resonance imaging data of 37 cases with hyperadrenocorticism were reviewed. Thirty-three cases underwent surgery; 4 Grade 5 cases did not have appropriate indications for surgery, and other therapies were used. Complete resection was achieved for 3, 3, 22 and 1 Grade 1A, 2A, 3A and 3B cases, respectively. Resection was incomplete in 1, 1 and 2 Grade 3A, 3B and 4B cases, respectively. Remission was achieved in 29 cases. Recurrence occurred in 4 cases, all of which were classified as Grade 3. Clinical Significance Dogs with Type A, Grade 1 to 3 hyperadrenocorticism had a good prognosis following trans-sphenoidal hypophysectomy. Grade 3B, 4 and 5 cases may not be suitable for this surgery.

術後創部の異常を早期に発見するためには、創部の疼痛や不快感などが重要な情報となる。しかし、動物看護においては、動物から症状の訴えを得ることは困難である。そのため、客観的な観察から早期に異常を発見することが求められる。そこで今回、外科手術後の看護動物2事例を対象とし、治療経過とともにサーモグラフィを用いた創部の観察を行った。その結果、1事例においては、腫脹・発赤を認めた創部がサーモグラフィ上で周辺部より高温を示し、肉眼的に炎症が消失し治癒が進行するに従い、創周囲との温度差が減少し均一な温度分布となった。また、2事例目では、創部に形成された潰瘍内において、組織が壊死している領域が低温を示し、創状態が悪化していることが確認された。以上、創部に炎症所見を認めた2事例に対して撮影を行うことで、創の状態を継続的にモニタリングすることができ、術後の創傷治癒過程の観察、創部の予後予測にサーモグラフィを用いることができる可能性が示された。(著者抄録)

Objective-To identify characteristics of chondrodystrophoid and nonchondrodystrophoid small-breed dogs with cervical intervertebral disk herniation (IVDH). Design-Retrospective case series. Animals-187 small-breed (<= 15 kg [33 lb]) dogs that underwent surgery because of cervical IVDH. Procedures-Medical records were reviewed for information on breed, sex, age, weight, location of affected intervertebral disks, duration and severity of neurologic signs, and recovery time. Results-55 of the 187 (29.4%) dogs were Beagles. The most frequently affected intervertebral disk was C2-3 (81/253 [32.0%]), and this was the more frequently affected intervertebral disk in dogs of several chondrodystrophoid breeds, including Beagles (29/66 [43.9%]), Dachshunds (13/37 [35.1%]), Shih Tzus (16/41 [39.0%]), and Pekingese (3/10 [30.0%]). However, caudal disks (C5-6 or C6-7) were more frequently affected in Yorkshire Terriers (13/24 [54.2%]) and Chihuahuas (9/13 [69%]). Shih Tzus and Yorkshire Terriers were significantly older at the time of surgery (mean +/- SD age, 9.6 +/- 2.3 years and 9.5 +/- 2.5 years, respectively) than were Pomeranians (6.2 +/- 2.3 years), and Yorkshire Terriers had a significantly higher number of affected disks (2.0 +/- 0.9) than did Dachshunds (1.1 +/- 0.3). Mean recovery time was significantly longer in Yorkshire Terriers (36.7 +/- 13.0 days) than in Beagles (16.5 +/- 17.1 days), Shih Tzus (17.8 +/- 14.5 days), or Chihuahuas (12.2 +/- 7.2 days). Conclusions and Clinical Relevance-Results suggested that there may be breed-specific differences in the characteristics of cervical IVDH in small-breed dogs.

Currently, the most commonly used bioresorbable scaffold is made of beta-tricalcium phosphate (β-TCP); it is hoped that scaffolds made of a mixture of hydroxyapatite (HA) and poly-D/L-lactide (PDLLA) will be able to act as novel bioresorbable scaffolds. The aim of this study was to evaluate the utility of a HA/PDLLA scaffold compared to β-TCP, at a loading site. Dogs underwent surgery to replace a section of tibial bone with a bioresorbable scaffold. After the follow-up period, the scaffold was subjected to histological analysis. The HA/PDLLA scaffold showed similar bone formation and superior cell and tissue infiltration compared to the β-TCP scaffold, as seen after Villanueva Goldner staining. Moreover, silver staining and immunohistochemistry for Von Willebrand factor and cathepsin K demonstrated better cell infiltration in the HA/PDLLA scaffold. The fibrous tissue and cells that had infiltrated into the HA/PDLLA scaffold tested positive for collagen type I and RUNX2, respectively, indicating that the tissue and cells that had infiltrated into the HA/PDLLA scaffold had the potential to differentiate into bone. The HA/PDLLA scaffold is therefore likely to find clinical applica

An 8-year-old male neutered standard dachshund was presented with a slowly growing mass in the left submandibular salivary gland. Histopathological examination revealed a tumour that was composed of bilayered duct-like structures with an inner layer of ductal cells and an outer layer of clear cells. Both inner and outer cells in the greater part of the tumour exhibited low to moderate atypia and low mitotic activity. However, a focal area towards the periphery showed enhanced cellular atypia and mitotic activity in tumour cells. Immunohistochemically, the outer layer of clear cells expressed myoepithelial markers, while the inner layer cells were positive for a luminal epithelial marker. No local recurrence or lymph node or distant metastasis was observed 18 months following surgery. Based on the morphology and immunohistochemical findings, a final diagnosis of epithelial-myoepithelial carcinoma with high-grade transformation was made. (C) 2015 Elsevier Ltd. All rights reserved.

Degenerative cranial cruciate ligament (CCL) rupture is characterized histologically by degenerating extracellular matrix (ECM) and chondroid metaplasia. Here, we describe the progression of chondroid metaplasia and the changes in the expression of ECM components in canine CCL rupture (CCLR). CCLs from 26 stifle joints with CCLR (CCLR group) and normal CCLs from 12 young beagles (control group) were examined histologically and immunohistochemically for expression of type I (COLD, type II (COLII), type III collagen (COLIII) and Sry-type HMG box 9 (SOX9). Cell density and morphology of CCLs were quantified using hematoxylin eosin staining. The percentage of round cells was higher in the CCLR group than in controls. COLI-positive areas were seen extensively in the connecting fibers, but weakly represented in the cytoplasm of normal CCLs. In the CCLR group, there were fewer COLT-positive areas, but many COLT-positive cells. The percentages of COLII-, COLIII- and SOX9-positive cells were higher in the CCLR group than in controls. The number of spindle cells with perinuclear halo was high in the CCLR group, and most of these cells were SOX9-positive. Deposition of COLT, the main ECM component of ligaments, decreased with increased COLIII expression in degenerated CCL tissue, which shows that the deposition of the ECM is changed in CCLR. On the contrary, expression of SOX9 increased, which may contribute to the synthesis of cartilage matrix. The expression of COLII and SOX9 in ligamentocytes showed that these cells tend to differentiate into chondrocytes.

Objective: To create a canine model of excessive tibial plateau angle (eTPA) and assess the chondroid metaplasia and extracellular matrix alteration in the cranial cruciate ligament. Methods: Seven mature female Beagles were included. Cylindrical osteotomy was performed bilaterally in the proximal tibia. The TPA was increased to approximately 40 degrees in the left tibia (eTPA stifle) and left unchanged in the right tibia (control stifle). Exercise stress was started at three months postoperatively, and at 12 months postoperatively the dogs were euthanatized and the cranial cruciate ligaments were collected. The specimens were subjected to haematoxylin and eosin staining to assess the ligamentocyte morphology and immunostaining to assess the type I (COLI), type II (COLII), and type III (COLIII) collagen, and the sry-type HMG box 9 (SOX9) staining. Results: Macroscopic cranial cruciate ligament injury was absent in six dogs but present in the eTPA stifle of one dog, which was excluded from the analysis. The ligamentocyte density decreased and the percentage of round ligamentocytes increased in the eTPA stifles. The COLII, COLIII, and SOX9 staining increased significantly and COLI deposition decreased in the eTPA stifles compared to the control stifle. Clinical significance: The extracellular matrix changed, COLI deposition decreased, and COLIII and SOX9 staining increased in the cranial cruciate ligament of the eTPA stifles. SOX9 may contribute to COLII synthesis in the extracellular matrix of the cranial cruciate ligament in eTPA stifles, and eTPA may promote chondroid metaplasia and extracellular matrix alteration.

Currently, the most commonly used bioresorbable scaffold is made of beta-tricalcium phosphate (beta-TCP); it is hoped that scaffolds made of a mixture of hydroxyapatite (HA) and poly-D/L-lactide (PDLLA) will be able to act as novel bioresorbable scaffolds. The aim of this study was to evaluate the utility of a HA/PDLLA scaffold compared to beta-TCP, at a loading site. Dogs underwent surgery to replace a section of tibial bone with a bioresorbable scaffold. After the follow-up period, the scaffold was subjected to histological analysis. The HA/PDLLA scaffold showed similar bone formation and superior cell and tissue infiltration compared to the beta-TCP scaffold, as seen after Villanueva Goldner staining. Moreover, silver staining and immunohistochemistry for Von Willebrand factor and cathepsin K demonstrated better cell infiltration in the HA/PDLLA scaffold. The fibrous tissue and cells that had infiltrated into the HA/PDLLA scaffold tested positive for collagen type I and RUNX2, respectively, indicating that the tissue and cells that had infiltrated into the HA/PDLLA scaffold had the potential to differentiate into bone. The HA/PDLLA scaffold is therefore likely to find clinical application as a new bioresorbable scaffold.

Hydroxyapatite (HA)/poly-l-lactide(PLLA) composite biomaterials are available for orthopedic applications, but bioresorption and cell-mediated inflammation in bone cortex are unknown. We conducted an 84-month follow-up study with Beagle dogs that were subjected to implants with either PLLA (left femur) or HA/PLLA (right femur). Histological and radiographic analysis showed that HA/PLLA screws induced significant increases in HA content from 36 months onward and complete burr hole closure at 60 months, whereas PLLA screws did not. Moreover, PLLA screws induced more severe fibrous tissue and histiocyte infiltration. HA/PLLA screws promote earlier burr hole replacement and have superior biocompatibility compared to PLLA screws.

近年、動物医療においてもリハビリテーションの重要性が認識され、治療行為のひとつとして注目を集めつつある。本研究では前十字靭帯断裂に馬尾症候群を併発した一事例を対象に術後リハビリテーションを行い、その有用性について検討した。術後早期からアイシングや他動的関節可動域運動(PROM運動)、マッサージ療法、温熱療法、水治療法を実施したところ、対照群と比べて膝関節の関節可動域の減少が小さく、筋肉量の減少は見られなかった。また、フォースプレートで解析した歩様回復までの期間は、対照群の3ヶ月に対し2ヶ月と短かった。これらの結果より、TPLO実施後早期からのリハビリテーションの効果は高く、術後回復の促進に有用であることが示唆された。日本の獣医療においてリハビリテーションがより広く普及し、麻痺や痛みを抱える患者動物とそのオーナーの苦しみを、少しでも減らす手助けとなることを期待する。

Objective: The aim of this study was to investigate the biomechanical effects of cranial cruciate ligament (CrCL) transection on stifle stability at three different stifle joint flexion angles using a robotic system. Methods: This was an ex vivo biomechanical study. Stifles (n = 6) were collected from the cadavers of Beagles weighing 10.5-12.0 kg. Six stifle joints were dissected, potted, and secured to the manipulator arms of a robotic simulator. With the stifle joint angle maintained at either hyperextension (151 degrees), 135 degrees or 90 degrees, stability was assessed by application of a 50 N load in either the cranial-caudal (CrCd test) or proximal-distal (PD test) directions. The stifle was given a cranial-caudal load of 50 N (CrCd test). A proximaldistal compression load of 50 N was then administered by the manipulator (proximal-distal test: PD test). The change in three-dimensional kinematics of the intact and the CrCL-transected stifles was compared between hyperextension, and 135 degrees and 90 degrees flexion for the CrCd and PD load conditions. A value of p<0.05 was considered statistically significant. Results: The cranial tibial displacements in the PD tests of the CrCL-transected stifles at 135 degrees (8.4 +/- 1.2 mm) and at 90 degrees (8.1 +/- 1.9 mm) were significantly greater than the displacement at 151.5 degrees (5.1 +/- 1.6 mm) (p = 0.004 and p = 0.012 respectively). Clinical significance: The canine stifle exhibited the most instability when the stifle flexion angle was 135 degrees.

Objectives: To evaluate the efficacy of cortical allograft and fibroblast growth factor 2 (FGF-2)-impregnated autogenous cancellous bone in nonunion fracture repair in dogs. Methods: From January 2000 to August 2010, seven dogs underwent cortical allograft and FGF-2-impregnated autogenous cancellous bone implantation for treatment of a femoral nonunion following fracture. Radiographic images were used to assess healing. Results: The average length of the implanted cortical allograft was 29.1 +/- 4.4 mm. A significant improvement in the postoperative percentage of femoral shortening was observed with the experimental treatment, from 85.2 +/- 8.2% to 95.0 +/- 4.8%. Using radiographic scoring, we analysed the process of bone remodelling. At three months post-surgery, the proximal and distal fracture lines had begun to disappear, and a complete absence was observed after six months. Bacterial infection was detected in two of the seven cases. Clinical significance: The findings of our study suggest that the combination of cortical allografts with FGF-2 impregnated cancellous autograft may be useful in cases of diaphyseal fracture non-union. The disappearance of the fracture line in dogs with nonunion was recognized at the same phase as the report in which healing process of allograft was evaluated in the experimental ostectomy model using the normal dog.

Objective-To evaluate the role of the semitendinosus muscle in stabilization of the canine stifle joint. Sample-Left stifle joints collected from cadavers of 8 healthy Beagles. Procedures-Left hind limbs, including the pelvis, were collected. To mimic the tensile force of the quadriceps, gastrocnemius, and semitendinosus muscles, wires were placed under strain between the ends of each muscle. A sensor was used to measure the tensile force in each wire. Specimens were tested in the following sequence: cranial cruciate ligament (CrCL) intact, CrCL transected, released (tensile force of semitendinosus muscle was released in the CrCL-transected stifle joint), and readjusted (tensile force of semitendinosus muscle was reapplied in the CrCL-transected stifle joint). Specimens were loaded at 65.3% of body weight, and tensile force in the wires as well as the cranial tibial displacement were measured. Results-Tensile force for the CrCL-transected condition increased significantly, compared with that for the CrCL-intact condition. Mean +/- SD cranial tibial displacement for the CrCL transected condition was 2.1 +/- 1.3 mm, which increased to 72 +/- 2.3 mm after release of the tensile force in the semitendinosus muscle. Conclusions and Clinical Relevance-Results supported the contention that the semitendinosus muscle is an agonist of the CrCL in the stifle joint of dogs. Moreover, the quadriceps and gastrocnemius muscles may be antagonists of the CrCL. These findings suggested that the risk of CrCL rupture may be increased by diseases (such as cauda equina syndrome) associated with a decrease in activity of the semitendinosus muscle. (Am J Vet Res 2012;73:672-680)